The show's final episode, {Counter-Clock Incident}, introduced the very first captain of the Enterprise, Robert April. Due to Gene Roddenberry's later request that the animated series not be considered canon, however, it has never been made part of official [Star Trek] continuity that Capt. April was the first captain of the USS Enterprise.

Sci-fi author [?] Peter David later integrated the characters of M'Ress and Arex into his book series [Star Trek: New Frontier], starting with the novel {Gateways #5: Cold Wars}.

One episode of this series revealed that Kirk's middle name is Tiberius.

In the episode, {Slaver Weapon}, writer Larry Niven introduced the cat-like alien race, the Kzinti, from his [Known Space] novels into the [Star Trek] universe.

When story editor D.C. Fontana was writing her episode {Yesteryear}, she ran into opposition from the network executives when they learned her story would have Spock's beloved pet mortally wounded and requiring euthanasia. The executives were concerned that it would upset young viewers and insisted that the pet be allowed to live. Gene Roddenberry supported Fontana and reassured the management that she would handle the story appropriately. As it turns out, there were never any complaints about the episode and the story is considered the finest of the series.

The episode {The Practical Joker} is essentially the origin of the holodeck.

In 1975, this series won a Daytime Emmy for Outstanding Entertainment Children's Series.

Originally the show was not going to include Nichelle Nichols, George Takei, and Walter Koenig due to budget considerations. However, when Leonard Nimoy learned about this, he refused to join the cast unless his friends were included. Rather than lose the most popular cast member, Filmation agreed to sign on Nichols and Takei. While Koenig could not be included because of the budget and, as a result, is the only regular cast member from the earlier series to never make an appearance, he did, however, write one episode: {The Infinite Vulcan}.

The "Star Trek Crews" from all the [Star Trek] series were ranked #2 in [TV Guide]'s list of the "25 Greatest Sci-Fi Legends" ({1 August 2004 issue}).